Patent GB-734667-A (GB)
Title: Improvements in or relating to carburation devices
IPC: F02M1/00
Filed: 1953-12-08
Abstract: 734,667. Carburetters. SOLEX. Dec. 8, 1953 [Dec. 30, 1952], No. 34141/53. Class 7(3). In a carburation device comprising a plurality of elements which come into operation successively one of the elements (called the first element) being employed to maintain the operation of the engine at low and medium speeds and comprising a throttle controlled directly by the user while the second element or each of the other elements comprises a throttle the opening of which is effected by pneumatic means in dependence upon the quantity of air sucked through the first element, the throttle of the second element is operated by an electromagnet device comprising an electromagnet energised when the quantity of air sucked through the first element of the device exceeds a predetermined value per unit of time. The device may be juxtaposed with at least a second carburation device operating like the first except for the fact that the throttle of the second element (or each of the throttles of the supplementary elements) of the second carburation device is controlled according to the flow of air sucked through the first element of the first carburation device. As shown a throttle valve 3 is controlled by the operator. A second throttle valve 4 is operable by a core 5 of a solenoid 6. The solenoid is arranged to be energised when the flow through a venturi 12 reaches a predetermined value. Thus suction from the venturi passes by way of an orifice 22 and passage (not shown) to the right hand side of a diaphram 11. When the suction reaches a predetermined value contacts 14, 17 are closed and the circuit of the solenoid is completed. The solenoid is connected to a point of the ignition circuit controlled by the switch 24, for example the input terminal of the ingition coil. The contact 14 may be carried by the diaphram. In a modification a second switch is provided in series with the contacts 14, 17. This switch being closed to earth the contact 17 when the throttle valve 3 reaches a predetermined position. The additional switch could be replaced by a flap valve or needle valve so controlled by the lever 25 that the right hand side of the diaphram communicates with the atmosphere through an orifice of calibrated cross-section when the butterfly valve takes up a position corresponding to an opening smaller than a predetermined minimum. A number of separate carburetters may be employed. A number of carburetters may deliver into a common manifold supplying all the cylinders of the engine. One carburetter could be of standard type while the other carburetters would be arranged to come into operation under control of a device similar to that described. In the case of a six cylinder engine comprising two carburetters and two separate inlet manifolds in which each carburetter and each manifold supplies three cylinders it would be possible to employ two carburetters of the type shown in Fig. 1 or two twin carburetters each comprising one butterfly valve controlled by the accelerator and a second butterfly valve controlled by a single electric contactor 10. This device could be situated between the two carburetters and the second butterfly valves would be controlled by the core 5. The closing of the valve 4 when the electromagnet is not energised is ensured by the weight of the core 5 but advantageously a stop 34 urges the valve 4 towards its closed position when the valve 3 is closed. A condenser 33 is provided.